Traveling wave tube amplifiers (TWTA) are used primarily in satellites as a power amplifier and are usually designed as traveling wave tube modules. These traveling wave tube modules comprise a traveling wave tube, which determines primarily the high frequency properties, and a power supply, which generates primarily the supply voltages for the traveling wave tube, a telemetry and/or telecommand interface to the satellite, as well as a control unit. The traveling wave tube module can be complemented with a pre-amplifier (also called a channel amplifier), which can also include a linearizer, which can also be integrated with other components in a housing. This combination is referred to as a high frequency power module.
A high frequency signal is amplified in a traveling wave tube by conveying an electron beam past a conductor that usually exhibits the shape of a helix and through which the high frequency signal flows. When the conductor and the electron beam are suitably configured, the energy from the electron beam can be transferred to the high frequency signal.
Traveling wave tube modules and, in general, amplifier modules are generally constructed in such a way that devices of the same type are interchangeable, so that a user can place them on the satellite in any way. In particular, a satellite can have a plurality of identically structured traveling wave tube modules, each of which is assigned a channel of the satellite; and these traveling wave tube modules are used to amplify the high frequency signal of the respective channel.
This means that the properties of the individual channels are not taken into consideration. After the amplifier modules are switched on, they can then be configured for the channel properties and/or type of mode per telecommand (i.e. by means of a command from a ground station). This configuration process has to be performed anew after each power on.